Guide clamps are tools that may be clamped to a workpiece or workbench and the like, for guiding a saw or other cutting tool, for cutting wood and the like.
The basic features of a guide clamp include a guide bar having a pair of gripping jaws at one side of the bar to clamp onto a workpiece, such as a board. One jaw, the clamping jaw, is at one end of the bar. The other jaw, the shifting jaw, may be positioned along the reach of the bar to bring the jaws against the edges of the workpiece to clamp the workpiece. The guide clamp may be used for various purposes, such as but not limited to, making markings on the workpiece, or as an abutment for a power hand saw which is held against the guide clamp as it makes a cut across the workpiece.
However, certain guide clamps are not always satisfactory for serving as an abutment for other types of power hand tools, such as a router. The vibration and other action of such a tool can move the tool away from the edge of the guide clamp even when it is tightly held.
U.S. Pat. No. 4,394,800 to Griset, the disclosure of which is incorporated herein by reference, describes an improved guide clamp, which positively holds and guides a tool across the workpiece. In this clamp, the shifting jaw is slidably carried on the guide bar to permit the workpiece to be embraced by the jaws. A pull rod associated with and parallel to the guide bar is connected to a lever on the clamp jaw. The shifting jaw locks onto this pull rod when the jaws embrace a workpiece and actuation of the lever then pulls the jaws together to clamp onto the workpiece and hold the guide clamp thereon. Guideways to guide and hold tools, jigs and the like are provided on the guide bar.